Converting cross lease to freehold title

I have been living in my house in Takapuna for about 17 years and am seriously considering selling it in the not too distant future. It has a cross lease title with another house located on the same title. The land area is approximately 1,200 sq metres and although my neighbour and I are joint (equal) owners of this parcel of land my exclusive use is around 570 sq metres whereas my neighbour's is about 400 sq. metres (the ROW passes my neighbour's house as my house is located at the back of the parcel of land).

From what I read from the thread of conversation in Property talk it would appear that it may be worth the trouble and expense for me to convert my cross lease to fee simple. By the way what is a fee simple? How different is it from an ordinary title? I have yet to approach my neighbour to suggest conversion as yet as I want to find out more first. I have just repainted the exterior of my house but did not know before that I may have to consult my neighbour on the change of colour